The present invention relates to an attachment arrangement, and more particularly to an attachment arrangement for components mounting within a vehicle transmission.
A hydraulically operated vehicle transmission is typically equipped with multiple frictional engaging elements such as hydraulic clutches, disks, brakes and the like that are engaged and disengaged by supplying/discharging operating oil to/from the frictional engaging elements. Proper operation and timing of the shift is achieved by optimizing the oil pressure for engagement/disengagement. The detection of the state of the clutch or other such frictional engagement elements is typically achieved by detecting the engaging oil pressure through an oil pressure sensor. The oil pressure sensor communicates with a transmission electronic control unit which commands the gear shit timing.
Ordinarily, the sensor is located within the transmission case which subjects the sensor to an extremely difficult environment. As a result, these components must be connected in a manner which is robust and impervious to the environment within the transmission case. Typically, multiple wire harnesses connect individual sensors to a connector extending through the transmission case. An external wire harness then provides communication between the sensors and the transmission electronic control unit. Only the sensors and their wire connections are located within the transmission case to avoid subjecting the electronic control unit to the difficult environment within the transmission case. Disadvantageously, the wire connections must routed within the transmission case to avoid multiple moving transmission components. In addition to the weight penalty of multiple wire harnesses, the routing may become rather complex and multiple wire connections may increase the possibility of failure.
Accordingly, it is desirable to provide a compact mounting arrangement for sensors and associated components which are resistant to the environment within a transmission case while minimizing wire connections and providing advantageous mounting versatility.
The transmission system according to the present invention provides a transmission housing having a mechatronics control module mounted therein. The mechatronics control module includes an electronic control unit having a flex foil circuit for the mounting of multiple electronic components including sensors which sense the hydraulic state of elements within the transmission system.
One embodiment of a sensor mounting arrangement provides a sensor which extends at least partially through a base plate. The base plate is layered with a flex foil such that a plurality of circuit traces on the flex foil are located opposite the base plate. The circuit traces are located to electrically communicate with a multiple of respective contacts extending from the sensor. Attachment members such as rivets mount the position sensor in an opening in the base plate and sandwich the flex foil there between
In another embodiment, a contact opening within the base plate and flex foil expose the sensor contacts. To allow communication between the circuit traces and the contacts, a flex foil flap is formed in the flex foil adjacent the contact opening. The flap is folded over so that the circuit traces are electrically attachable to the sensor contacts.
Another embodiment of a sensor mounting arrangement provides an extended flex foil portion which extends beyond the periphery of the base plate. The sensor is attached to the extended flex foil portion and is folded over an edge of the base plate. The sensor is thereby mountable to the base plate on the side opposite the flex foil.
Another embodiment provides a base plate that includes a recessed area for receipt of a sensor. The recessed mounting provides many base plate attachment advantages including improving the seal between the base plate and the hydraulic control unit. A contact opening in the base plate is located to allow receipt of sensor contacts from one side, and a flex foil flap from the opposite side. The flex foil flap extends into the contact opening in a cantilever manner. As the sensor is mounted into the recessed area, the contacts are aligned with the contact opening and are pushed past the flex foil flap to emerge on the opposite side thereof to allow attachment with the circuit traces.
The present invention therefore provides a compact mounting arrangement for sensors and associated components which are resistant to the environment within a transmission case, minimize wire connections, and provide extensive mounting versatility.